Various apparatus and techniques exist for boresighting. Generally speaking, relatively costly optical devices are used for this purpose.
Many of the existing optical devices are unsuitable for use in the field, which is typically a dusty and high-vibration environment. The existing optical devices have costly precision optical parts which often must be realigned in the field. This is often time-consuming and difficult and the resultant accuracy is not as precise as is desired. Additionally, the realignment typically cannot be done in real-time.